Evaluating the extent and impact of the extreme Storm Gloria on Posidonia oceanica seagrass meadows

Extreme storms can trigger abrupt and often lasting changes in ecosystems by affecting foundational (habitat-forming) species. While the frequency and intensity of extreme events are projected to increase under climate change, its impacts on seagrass ecosystems remain poorly documented. In January 2020, the Spanish Mediterranean coast was hit by Storm Gloria, one of the most devastating recent climate events in terms of intensity and duration. We conducted rapid surveys of 42 Posidonia oceanica meadows across the region to evaluate the extent and type of impact (burial, unburial and uprooting). We investigated the significance of oceanographic (wave impact model), geomorphological (latitude, depth, exposure), and structural (patchiness) factors in predicting impact extent and intensity. The predominant impact of Storm Gloria was shoot unburial. More than half of the surveyed sites revealed recent unburial, with up to 40 cm of sediment removed, affecting over 50 % of the meadow. Burial, although less extensive, was still significant, with 10–80 % of meadow cover being buried under 7 cm of sediment, which is considered a survival threshold for P. oceanica. In addition, we observed evident signs of recently dead matte in some meadows and large amounts of detached drifting shoots on the sea bottom or accumulated as debris on the beaches. Crucially, exposed and patchy meadows were much more vulnerable to the overall impact than sheltered or continuous meadows. Given how slow P. oceanica is able to recover after disturbances, we state that it could take from decades to centuries for it to recoup its losses. Seagrass ecosystems play a vital role as coastal ecological infrastructure. Protecting vulnerable meadows from anthropogenic fragmentation is crucial for ensuring the resilience of these ecosystems in the face of the climate crisis.This study was funded by the CSIC project “Effects of storm Gloria on the western Mediterranean meadows (202030E052) and “Storms of change: as phenomena extreme weather alters Mediterranean coastal ecosystems, their services and their perception by society" (PID2020-113745RB-I00), state program of I+D+I Oriented to the Challenges of the Society and within the framework of the activities of the Spanish Government through the "Maria de Maeztu Centre of Excellence” accreditation to IMEDEA (CSIC-UIB) (CEX2021-001198). We want to thank the SPAS (Society of Fishing and Underwater Activities of Mataró) and the Mataró City Council, which has financed 25 years of the Alguer de Mataró project

Abundancia y parámetros poblacionales de "Octopus vulgaris" aplicando un modelo de captura-recaptura espacialmente explícito en ambientes antrópicos (Port d'Antratx, Mallorca)

[Resumen:] El pulpo común Octopus vulgaris Cuvier, 1797 es una especie de gran interés económico y ecológico en las costas españolas y en el resto de la cuenca Mediterránea. A pesar de ello, aún son muy escasos los estudios acerca de su abundancia o sus patrones de distribución. Sus poblaciones juegan un papel relevante en multitud de ecosistemas bentónicos costeros, ya que su presencia puede influenciar directamente sobre la dinámica y diversidad del ecosistema. Los modelos espaciales de captura - recaptura (SCR) permiten el estudio de abundancias y parámetros poblacionales de O. vulgaris, ampliando los horizontes de experimentación para el orden de los octópodos. El objetivo principal de este estudio consiste en estimar simultáneamente mediante un método de implementación Bayesiano la abundancia de O. vulgaris en una localidad costera antropizada de las islas Baleares (Port d´Andratx), la tasa de reclutamiento y mortalidad de dicha población y el área de actividad (home range) a nivel individual. El muestreo estuvo basado en la colocación de 5 líneas de trampas (nasas cebadas y cadufos) durante 64 días, en los cuales se capturaron 72 ejemplares. El marcaje de los individuos se efectuó mediante marcas de aplicación subcutánea (PIT-tags) y se recapturaron un total de 19 pulpos marcados (tasa de recaptura: 26,4%). El análisis de los datos de captura - recaptura requirió la implementación de un modelo espacial Jolly - Seber que consideró a la población como abierta. A su vez, el tiempo de muestreo fue dividido en cuatro periodos de pesca. Las estimas de la abundancia poblacional de O. vulgaris obtenidas dentro de cada periodo de pesca se acoplan al ciclo de vida de la especie. Los resultados sugieren un aumento poblacional en el primer periodo de muestreo, reflejando el posible asentamiento de los juveniles. Posteriormente, se produce una disminución de la población debida a un gran descenso del aporte de individuos a la población (inmigración y/o supervivencia) y una mortalidad o emigración estable. El home range estimado para los individuos varía entre 27.954 m2 - 73.274 m2, con un radio medio de 121,85 m. Los resultados muestran la importancia de ambientes costeros antropizados para las poblaciones de pulpo, y el método implementado en este estudio permite obtener estimas precisas de los parámetros poblacionales descritos. Aumentar el número de capturas y recapturas mediante un mayor esfuerzo de muestreo en los diferentes ambientes donde habita esta especie, es esencial para comprender mejor tanto la dinámica, como los movimientos de las poblacionales de O. vulgaris.[Abstract:] Capture - recapture methods can fix the conventional techniques inherent limitations. The common octopus Octopus vulgaris Cuvier, 1797 presents a great economic and ecological interest in the Spanish coasts and throughout the Mediterranean basin, but there are still very few studies related to its abundance or distribution patterns. O. vulgaris populations play an important role in multitude of coastal benthic ecosystems, given that their presence can directly influence the dynamics and diversity of coastal ecosystems. Spatial capture - recapture (SCR) models allow the study of abundance and population parameters of O. vulgaris, expanding the horizons of octopods experimentations. The main objective of this study consists on estimating simultaneously the abundance, recruitment and mortality rates of O. vulgaris population in an anthropic coastal area of the Balearic Islands (Port d´Andratx) through a Bayesian approach, but also individual activity area (home range). Sampling was carried out setting 5 independent lines with octopus traps (baited traps and plastic-pots) for 64 days, capturing a total of 72 different octopuses. Captured individuals were tagged with subcutaneous tags (PIT-tags) and a total of 19 tagged octopuses were recaptured throughout the study period (recapture rate: 26.4%). Capture - recapture data analysis required a Jolly-Seber spatial model implementation considering an open population and dividing the study into four fishing periods. Estimations of O. vulgaris abundances within each fishing period fitted with the life-history of this species. Results suggest a population increase at the first period, showing the potential settlement of juveniles. Later, a population decrease happens due to a significant recruitment decrease (immigration and/or survival) and a constant mortality/emigration throughout the study period. The individual home range ranged from 27,954 m2 to 73,274 m2, and the mean radius was 121.5 m. Results show the relevance of human-altered coastal habitats for O. vulgaris populations, and the method developed in this research allows obtaining accurate estimates of the population parameters successfully. Increasing the number of catches and recaptures through a greater sampling effort at different coastal environments where this species inhabits is essential to better-understand the dynamic and movements of O. vulgaris populations.Traballo fin de mestrado (UDC.CIE). Bioloxía mariña. Curso 2016/201

Species‐specific acclimatization capacity of key traits explains global vertical distribution of seagrass species

AimThe global vertical depth distribution of seagrass species remains poorly understood. Locally, the abundance and distribution of seagrasses is determined by light penetration, but at global levels each seagrass species has very distinct maximum distributional depth ranges, indicating that plant-associated traits must also influence their specific depth ranges. Seagrass-specific attributes, such as plant size or architecture, growth or reproductive strategy and their physiological and/or morphological acclimatization potential, have been suggested to be responsible for this variety of vertical distributions. We investigate here whether these species-specific traits drive differences in the global maximum vertical distribution of seagrasses.LocationGlobal.Time periodPublications between 1982 and 2020.Major taxa studiedSeagrasses (order Alismatales).MethodsWe tested whether the species-specific maximum vertical distribution of seagrasses can be predicted by (1) their rhizome diameter (a proxy for plant size); (2) their functional resilience (growth/reproductive strategy); or (3) their acclimatization capacity. For the last aspect, we used a systematic review followed by meta-analytical approaches to select key seagrass traits that could potentially acclimatize to extreme light ranges across different seagrasses.ResultsWe found that vertical distribution is best explained by the species-specific acclimatization capacity of various seagrass traits, including saturation irradiance (physiological trait), leaves per shoot (morphological trait) and above-ground biomass (structural trait). In contrast, our results indicate no predictive power of seagrass size or growth/reproductive strategy on the vertical distribution of seagrasses.Main conclusionsAcross the globe, the ability of seagrass species to thrive at a wide range of depths is strongly linked to the species-specific acclimatization capacity of key traits at different organizational levels

Quantifying the role of photoacclimation and self-facilitation for seagrass resilience to light deprivation

Introduction: Light gradients are ubiquitous in marine systems as light reduces exponentially with depth. Seagrasses have a set of mechanisms that help them to cope with light stress gradients. Physiological photoacclimation and clonal integration help to maximize light capture and minimize carbon losses. These mechanisms can shape plants minimum light requirements (MLR), which establish critical thresholds for seagrass survival and help us predict ecosystem responses to the alarming reduction in light availability.Methods: Using the seagrass Cymodocea nodosa as a case study, we compare the MLR under different carbon model scenarios, which include photoacclimation and/or self-facilitation (based on clonal integration) and that where parameterized with values from field experiments.Results: Physiological photoacclimation conferred plants with increased tolerance to reducing light, approximately halving their MLR from 5-6% surface irradiance (SI) to ≈ 3% SI. In oligotrophic waters, this change in MLR could translate to an increase of several meters in their depth colonization limit. In addition, we show that reduced mortality rates derived from self-facilitation mechanisms (promoted by high biomass) induce bistability of seagrass meadows along the light stress gradient, leading to abrupt shifts and hysteretic behaviors at their deep limit.Discussion: The results from our models point to (i) the critical role of physiological photoacclimation in conferring greater resistance and ability to recover (i.e., resilience), to seagrasses facing light deprivation and (ii) the importance of self-facilitating reinforcing mechanisms in driving the resilience and recovery of seagrass systems exposed to severe light reduction events

Quantifying the role of photoacclimation and self-facilitation for seagrass resilience to light deprivation

Light gradients are ubiquitous in marine systems as light reduces exponentially with depth. Seagrasses have a set of mechanisms that help them to cope with light stress gradients. Physiological photoacclimation and clonal integration help to maximize light capture and minimize carbon losses. These mechanisms can shape plants minimum light requirements (MLR), which establish critical thresholds for seagrass survival and help us predict ecosystem responses to the alarming reduction in light availability.Funding was provided by grant UMBRAL, CTM2017-86695-C3-3-R and CTM2017-86695-C3-1-R, as well as grant STORM, PID2020-113745RB-I00 from the Spanish Agency of Research (AEI-MICINN) and European funding (FEDER/ERDF). MM-F was funded by grant PRE2018-085778 from the Spanish FPI PhD scholarships program. JB acknowledges the support received by the Spanish Ministry of Science and Innovation under the JdC fellowship (FJC2018-035566-I) and the European Commission – European Union’s Horizon 2020 MSCA – SHIFT2SOLVE-1030591. MA’s contribution was funded by an Australian Research Council (ARC) Discovery Early Career Researcher Award (DE200100683).Peer reviewe

Nutrient Regimes Determine the Strength of Herbivore-Mediated Stabilizing Feedbacks in Barrens

VIII International Symposium on Marine Sciences, 6-8 July 2022, Las Palmas de Gran Canaria, EspañaThe last few decades have seen a rapid spread of barrens on temperate rocky reefs as sea urchin overgrazing of marine forests causes habitats to shift to more depauperate stable states. Reversing these trends requires a proper understanding of the novel ecological feedbacks that maintain rocky barrens and the conditions under which they operate. In this study, we explored the role of a secondary herbivore (a grazing limpet) in reinforcing the stability of barrens formed under different nutrient conditions. Combining comparative and field experimental studies in two Mediterranean regions characterized by contrasting nutrient regimes, we assessed: (i) if the creation of barren areas by sea urchins enhances limpet abundance, (ii) the grazing impact by limpets through foraging marks (halos), and (iii) the ability of limpets to maintain barrens in the absence of sea urchins. Our results show that sea urchin overgrazing of erect macroalgae enhanced limpet abundance in both nutrient regimes. The effects of limpet grazing on macroalgal assemblages varied with nutrient regimes being up to six times more intense under oligotrophic conditions. Finally, we found that limpets were able to maintain barrens in the absence of the sea urchins only under low nutrient regimes. Our results suggest greater vulnerability of subtidal forests to overgrazing in oligotrophic regions and demonstrate the importance of environmental settings in regulating ecosystem feedbacks mediated by plant-herbivore interactionsThis study is developed on the framework of the Project UMBRAL (CTM2017-86695-C3-1R) with funding from the Spanish Ministry of Science and Innovation. J Boada acknowledges funding from the Spanish Ministry of Science and Innovation (FJC2018-035566-I) and the European Commission – European Union’s Horizon 2020 MSCA – SHIFT2SOLVE-1030591.We also acknowledge the contribution of the I+D+I Project CriMa (RTI2018-095770-B100; MCIU/AEI/FEDER, EU) to attend to the ISMS symposiumPeer reviewe

Nutrient conditions determine the strength of herbivore‐mediated stabilizing feedbacks in barrens

13 pages, 5 figures, 5 tables, supporting information https://doi.org/10.1002/ece3.9929.-- Data Availability Statement: The data used in this study will be made publicly available at the Dryad open repository (https://datadryad.org/stash)Abiotic environmental conditions can significantly influence the way species interact. In particular, plant–herbivore interactions can be substantially dependent on temperature and nutrients. The overall product of these relationships is critical for the fate and stability of vegetated ecosystems like marine forests. The last few decades have seen a rapid spread of barrens on temperate rocky reefs mainly as a result of overgrazing. The ecological feedbacks that characterize the barren state involve a different set of interactions than those occurring in vegetated habitats. Reversing these trends requires a proper understanding of the novel feedbacks and the conditions under which they operate. Here, we explored the role of a secondary herbivore in reinforcing the stability of barrens formed by sea urchin overgrazing under different nutrient conditions. Combining comparative and experimental studies in two Mediterranean regions characterized by contrasting nutrient conditions, we assessed: (i) if the creation of barren areas enhances limpet abundance, (ii) the size-specific grazing impact by limpets, and (iii) the ability of limpets alone to maintain barrens. Our results show that urchin overgrazing enhanced limpet abundance. The effects of limpet grazing varied with nutrient conditions, being up to five times more intense under oligotrophic conditions. Limpets were able to maintain barrens in the absence of sea urchins only under low-nutrient conditions, enhancing the stability of the depauperate state. Overall, our study suggests a greater vulnerability of subtidal forests in oligotrophic regions of the Mediterranean and demonstrates the importance of environment conditions in regulating feedbacks mediated by plant–herbivore interactionsJ Boada acknowledges funding from the Spanish Ministry of Science and Innovation (FJC2018-035566-I) and the European Commission – European Union's Horizon 2020 MSCA – SHIFT2SOLVE-1030591. T Alcoverro acknowledges funding from the Spanish Ministry of Science and Innovation – Project UMBRAL (CTM2017-86695-C3-1R). F. Bulleri acknowledges support from the FutureMARES project, funded from the European Union's Horizon 2020 research and innovation program under grant agreement No. 869300With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)Peer reviewe